Abstract: A two-stroke engine in a hand-held working tool such as a motor chainsaw has a combustion chamber delimited by a piston which drives a crankshaft. An outlet for removing exhaust gases from the combustion chamber and an intake for supplying fresh mixture to the combustion chamber are provided. A storage duct opens into the intake and the crankcase and is connected with a carburetor. Combustion air flows via a crankcase intake and a transfer passage into the combustion chamber. For providing good power development with good exhaust emission values under all operating conditions, the flow cross-section of the mixture-forming channel leading to the storage duct is smaller by more than one half than the flow cross-section of the intake passage leading to the crankcase intake. During idle, the fuel required for operation is supplied substantially exclusively via the mixture-forming channel leading to the storage duct.

Abstract: A snap closure is provided for the detachable securement of a housing cover on a housing of a manually-guided implement, especially to secure an air filter cover that covers an air filter of an internal combustion engine for driving a tool of the implement. At least one snap hook is provided on one of the components that are to be secured together, namely the cover and the housing. The snap hook is provided on an end of an elastically deflectable leg that is disposed on the one component. The snap hook is tapered in the manner of a detent and when the cover is mounted on the housing the snap hook, accompanied by an elastic return force, is engagable in an undercut provided on the other component. The snap hook is deflectable in or parallel to a surface plane on the one component that carries the snap hook.

Abstract: A hedge trimmer has a tool that is driven by a drive unit. At least one vibration-dampened handle is secured to the drive unit. The handle comprises a one-piece component having a grip portion and a mounting portion for mounting on the drive unit. To simplify mounting of the handle, the grip portion and the mounting portion are interconnected by a vibration-dampening intermediate portion. The mounting portion along with the intermediate portion and the grip portion form the one-piece or monolithic component.

Abstract: A manually guided, portable implement, especially a power saw, is provided. The implement has a cylinder and a crankshaft that is connected to a piston via a piston rod. The implement has an essentially plastic housing as well as a lower crankcase. A stabilizing plate is nearly entirely embedded in the material of the lower crankcase. The one-piece stabilizing plate is provided with support sockets for bolting the lower crankcase to the cylinder. An overall metallic screw connection can thus be established.

Abstract: A muffler for the exhaust gas of an internal combustion engine is provided. The muffler has a housing with an inlet opening and an outlet, and surrounds a muffling chamber. In the flow path of the exhaust gas a spark arrestor screen, and on the side of the inlet opening an exhaust gas diffuser, are provided. The muffling chamber is divided by a partition into a first and second partial chamber. The volume of the second partial chamber corresponds at least approximately to the volume of the first partial chamber. The spark arrestor screen is disposed in the partition.

Abstract: A manually guided suction device or blower is provided that has a housing in which is formed a spiral blower path in which is disposed an impeller that is rotatably driven by a drive motor. The spiral blower path has an air-conveying air inlet and an air-withdrawing outlet. A connector is provided for the detachable connection of an air-conveying connection conduit, whereby when the connection conduit is mounted it overlaps with the connector, which is secured to the housing, over a prescribed axial length. To achieve a mechanically secure connection, an annular sealing element is held in a groove in a surface of the connector or connection conduit in the overlap region, wherein over the entire circumference thereof, the sealing element projects beyond such surface.

Abstract: A manually guided implement having a drive motor is provided. Control elements, such as a gas throttle and an arresting element, are pivotably disposed on a grip of the implement disposed remote from the motor. The arresting element is fixed in position on the throttle by a pivot joint, and is held in a position of rest by a spring element. The arresting element can be pivoted out of the rest position into an arresting position by the hand of an operator. The arresting position defines a starting throttle position of the gas throttle on the grip of the implement.

Abstract: An implement is provided and has a drive motor secured to one end of a carrying tube and connected via a drive shaft in the tube with the other end of the tube. A first handle is disposed on the tube in the vicinity of the drive motor and is spaced from a second handle. To support the forearm of an operator, a supporting device is provided that extends in the longitudinal direction of the carrying tube in the direction toward the drive motor. The longitudinal axis of the supporting device forms an angle of less than 90° with the carrying tube and is open toward the drive motor.

Abstract: A mounting mechanism for an adjustable component that is to be held against an abutment surface of a housing, especially for the guide bar of a power chain saw, is provided. The mechanism includes at least two bolts that are provided on the housing, are spaced from one another, and project beyond the abutment surface of the housing and into an elongated opening of the component. At least one device is provided that extends into a gap between one of the bolts and at least one of the longitudinal edges of the elongated opening for engaging such at least one longitudinal edge.

Abstract: A blower for cleaning a surface is provided. The blower includes a radial blower that is driven by a motor and includes an impeller that is rotatable about a blower axis and a housing that at least partially surrounds the impeller. In the area of the blower axis, the housing is provided with an intake opening on an end wall that is disposed approximately perpendicular to the blower axis. A damping bell is disposed on the end wall in the region of the intake opening. The damping bell is provided with a damping panel that is disposed approximately parallel to and at a distance from the end wall, and covers the intake opening. The damping bell also includes a bell wall that extends about the intake opening and the damping panel in a collar-like manner. At least one intake window is provided in the bell wall.

Abstract: A hand-held work tool has a housing with a carburetor heater and a grip heater. An internal combustion engine is mounted in the housing and has a crankshaft and an ignition system. The ignition system has a pole wheel with permanent magnets fastened sequentially at a periphery of the pole wheel in the circumferential direction. Charge armatures are mounted in the housing and close the magnetic circuit between neighboring permanent magnets. The charge armatures have legs and excitation coils mounted on the legs. Upon rotation of the pole wheel, the permanent magnets generate an electric current in the excitation coils, wherein a first set of excitation coils is combined to a first partial generator and connected to an electric circuit of the carburetor heater and a second set of the excitation coils is combined to a second partial generator and connected to an electric circuit of the grip heater such that the electric current is supplied respectively to the carburetor heater and the grip heater.

Abstract: An exhaust gas muffler for an internal combustion engine has a housing having an inlet and an outlet for engine exhaust gas. The housing has walls defining the interior of the housing. The housing has a first housing shell having a first connecting flange and a second housing shell having a second connecting flange, wherein the first and second connecting flanges are fastened to one another in a common flange plane. Each housing shell has a bottom. A partition is mounted in the housing and divides the interior of the housing into two compartments. The two compartments are connected by flow connections allowing passage of the engine exhaust gas between the two compartments. The partition has opposed ends supported respectively on the bottoms of the housing shells. The partition has two wall portions curved outwardly in opposite directions relative to a plane of the partition and has multiple openings.

Abstract: A venting valve for a fuel tank of a working tool driven by an internal combustion engine has a pressure compensation channel connecting the fuel tank interior to the surrounding atmosphere. A valve seat and a diaphragm are provided for closing off the pressure compensation channel when the diaphragm is seated on the valve seat. The diaphragm is lifted off the valve seat to open the pressure compensation channel when vacuum is present in the fuel tank interior. The valve seat is located at a first side of the diaphragm facing away from the fuel tank interior. The diaphragm has a central opening arranged centrally relative to the valve seat. A support plate is positioned at a second side of the diaphragm facing the fuel tank interior. It covers the deflecting area of the diaphragm and supports the diaphragm. The support plate has a sealing bead positioned in alignment with the valve seat. The spring forces the support plate and the diaphragm against the valve seat.

Abstract: An anti-vibration element has a tubular elastic base body with a first and a second end for connecting parts in a vibration-damping manner. A dumbbell-shaped bolt has a connecting element and a first and a second clamping element connected to opposite ends of the connecting element. The dumbbell-shaped bolt is inserted into the base body such that the dumbbell-shaped bolt has limited axial displacement. The connecting element can be made of a substantially rigid or a substantially elastic material. In a preferred embodiment, the first clamping element is axially fixed relative to the longitudinal axis of the base body and the second clamping element is axially displaceable relative to the longitudinal axis of the base body.

Abstract: An internal combustion engine has a crankcase and a cylinder with an outlet with a first flange. A muffler having an inlet with a second flange is connected to the outlet with the inlet. The muffler is formed as a unitary part. The first flange has a first flange surface and the second flange has a second flange surface, whereby the first flange surface and the second flange surface contact one another so as to form a flange connection. At least two slip-on clamps are connected to a circumference of the flange connection. The clamp has substantially the shape of a bracket with two legs extending in the same direction. The legs have inner surfaces facing one another. The flange connection has receiving surfaces for the legs wherein the inner surfaces of the legs cooperate with the receiving surfaces so as to force the first and the second flange surfaces against one another.

Abstract: A protective shield for a free-cutting tool having a rotatable cutting head with a cutting thread that extends radially upon rotation of the cutting head and thus defines a cutting plane, has a support section for fixedly connecting the shield to the tool above the cutting plane. A circumferential wall is connected to the support section and extends about a portion of the circumference of the cutting plane. The circumferential wall extends axially from the support section to at least the cutting plane and has axially extending lateral edges arranged perpendicular to a direction of rotation of the cutting head. The lateral edges each have a round transition into a bottom edge of the circumferential wall. A crosscutting blade for cutting to length the cutting thread is connected to the inside of the circumferential wall at its leading portion in the direction of rotation. The crosscutting blade extends over the axial height of the circumferential wall.

Abstract: A carburetor for internal combustion engines, especially for very small portable engines. The carburetor has a control chamber arranged in the carburetor in the fuel supply to the intake pipe. The control chamber is connected with the intake pipe via inlet passages, the rate or quantity of flow through which can be regulated, and is connected with fuel feed supplied by a fuel pump via an inlet valve, which is biased in the closed position. The inlet valve is opened by a control membrane which delimits the control chamber. The control membrane, on that side thereof remote from the control chamber, delimits an equalizing chamber along with a closure cover fastened to the carburetor housing. The equalizing chamber is constructed as a pressure chamber which can be selectively connected via a reversing or change-over valve with either the crankcase housing of the internal combustion engine, or with the atmosphere.

Abstract: A portable motor chain saw with a safety braking device to protect against kick-back, recoil or centrifugal movements of the saw. The saw includes a handle supported against the motor housing by damping elements, and also includes a locking device which on the one hand is connected with the handle, and on the other hand engages against a hand guard in such a way that it is released under the influence of relative movement, of the motor housing with respect to the handle, caused by a kick-back or centrifugal movement, consequently releasing the hand guard. The locking device has an abutment surface extending transverse to the direction of centrifugal movement, and this abutment surface cooperates with a projection directed against it.

Abstract: Disclosed is a portable motorized chain saw, comprising: a chain sprocket; clutch means positioned between the chain sprocket and the drive shaft of the motor for selectively coupling the chain sprocket with the drive shaft, the clutch means including a drum member; and a brake band positioned in contiguous relationship with the outer circumferential surface of the drum member and including one or more oil stripping openings therein.

Abstract: Disclosed is an exhaust silencer suitable for use with portable combustion engines, and particularly for use with chain saw engines, comprising a chamber having an inlet and outlet for receiving the engine exhaust; means disposed about the chamber outlet for reducing the kinetic energy of the exhaust flowing therethrough; and an air duct means mounted exteriorly of the chamber below the chamber outlet for cooling the chamber, the kinetic energy reducing means, and the exhaust gas by contact with a stream of ambient air flowing therethrough.